The present disclosure relates to a thin-film transistor using an oxide semiconductor, a display unit including the thin-film transistor, and an electronic apparatus including the display unit.
It is known that oxides of zinc, indium, gallium, tin, and mixtures thereof (hereinafter referred to as “oxide semiconductors”) exhibit favorable semiconductor properties, and in recent years, applications of the oxide semiconductors to thin-film transistors (hereinafter referred to as “TFTs”) as drive devices of active matrix display units have been actively studied. For example, a mixed oxide of zinc, indium, and gallium (hereinafter referred to as “IGZO”) exhibits electron mobility 10 or more times as high as that of amorphous silicon used as a semiconductor in related art; therefore, applications of IGZO to large-screen high-definition high-frame-rate liquid crystal display units and organic EL display units are strongly desired.
For the formation of a bottom-gate TFT, it is proposed to form a channel protective layer on an entire surface of an oxide semiconductor layer and to connect source and drain electrodes to the oxide semiconductor layer through connection holes (contact holes) formed in the channel protective layer (for example, refer to Japanese Unexamined Patent Application Publication No. 2010-135462). By doing so, the TFT is formed with use of fewer masks while protecting the oxide semiconductor layer by the channel protective film during a process of forming the TFT.